Release 3.0: DB_RMW

The following change applies only to applications using the
Berkeley DB Concurrent Data Store product. If your application is not using that product,
you can ignore this change.

Historically, the DB->cursor() method took the DB_RMW flag to indicate
that the created cursor would be used for write operations on the
database. This flag has been renamed to the DB_WRITECURSOR
flag.

The application should be searched for any occurrences of DB_RMW. For
each of these, any that are arguments to the DB->cursor() function
should be changed to pass in the DB_WRITECURSOR flag instead.